package com.qiang.test12;

import java.util.ArrayList;

public class Demo06 {
    public static void main(String[] args) {
        ArrayList<String> list = new ArrayList<>();
        list.add("12");
        list.add("23");
        list.add("45");
        list.add("56");
        boolean contains = list.contains("12");
        System.out.println(contains);
    }
}
